Synthesis of the Derivatives of 4-(5-Aryl-3-methylfuran-3-yl)-1,2,3-thiadiazole and Functionalization of 5-Aryl-2- methylfuran via Reactions of Thiadiazole Ring

Abstract

By arylation of 2-methyl-3-acetylfuran via the Gomberg–Bachmann reaction 5-(4-ethoxycarbonylphenyl)-, 5-(2-nitrophenyl), and 5-(4-nitrophenyl)-2-methyl-3-acetylfurans were synthesized. Carboethoxyhydrazones of 2-methyl-5-phenyl-3-acetylfuran and its phenyl-substituted analogs when treated with thionyl chloride form 4-(5-aryl-2-methylfuran-3-yl)-1,2,3-thiadiazoles by the Hurd–Mori reaction. Thermal stability of obtained compounds increases with the increase in electron-acceptor action of substituent in phenyl ring. Opening of thidiazole ring in the compounds synthesized under the action of potassium tert-butylate in THF in the presence of alkyl iodides leads to the corresponding alkylthioethynylfurans. Performing the reaction with potassium carbonate in DMF in the presence of excess morpholine permits the preparation of (2-methyl-5- arylfuran-3-yl)thioacetylmorpholides.